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<td ><a href="../qtdoc/index.html">Qt 5.12</a></td><td ><a href="qtqml-index.html">Qt QML</a></td><td ><a href="qtqml-qmlmodule.html">QML Types</a></td><td >Number QML 类型</td></tr></table><table class="buildversion"><tr>
<td id="buildversion" width="100%" align="right"><a href="qtqml-index.html">Qt 5.12.3 参考指南</a></td>
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<h3><a name="toc">目录</a></h3>
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<li class="level1"><a href="#methods">方法</a></li>
<li class="level1"><a href="#details">详细信息</a></li>
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<h1 class="title">Number QML 类型</h1>
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<!-- $$$Number-brief -->
<p>Number对象提供了一个数字值。 <a href="#details">更多...</a></p>
<!-- @@@Number -->
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<tr><td class="memItemLeft rightAlign topAlign"> 导入语句:</td><td class="memItemRight bottomAlign"> import QtQml 2.12</td></tr></table></div><ul>
<li><a href="qml-qtqml-number-members.html">所有成员的列表，包括继承成员</a></li>
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<a name="methods"></a>
<h2 id="methods">方法</h2>
<ul>
<li class="fn">string <b><b><a href="qml-qtqml-number.html#fromLocaleString-method">fromLocaleString</a></b></b>(<i>locale</i>, <i>number</i>)</li>
<li class="fn">string <b><b><a href="qml-qtqml-number.html#toLocaleCurrencyString-method">toLocaleCurrencyString</a></b></b>(<i>locale</i>, <i>symbol</i>)</li>
<li class="fn">string <b><b><a href="qml-qtqml-number.html#toLocaleString-method">toLocaleString</a></b></b>(<i>locale</i>, <i>format</i>, <i>precision</i>)</li>
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<h2 id="details">详细信息</h2>
<p>QML Number对象使用区域感知函数扩展了JS Number对象。</p>
<p><b>请参考 </b><a href="qml-qtqml-locale.html">Locale</a><span lang="zh-cn">。</span></p>
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<h2>Method Documentation</h2>
<!-- $$$fromLocaleString -->
<div class="qmlitem"><div class="qmlproto">
<div class="table"><table class="qmlname">
<tr valign="top" class="odd" id="fromLocaleString-method">
<td class="tblQmlFuncNode"><p>
<a name="fromLocaleString-method"></a><span class="type"><a href="qml-string.html">string</a></span> <span class="name">fromLocaleString</span>(<i>locale</i>, <i>number</i>)</p></td></tr>
</table></div>
</div><div class="qmldoc"><p>使用提供的语言环境约定解析Number，返回Number。</p>
<p>如果没有提供区域设置，将使用默认区域设置。</p>
<p>例如，使用德语区域设置:</p>
<pre class="cpp">

  var german <span class="operator">=</span> <span class="type"><a href="qml-qtqml-qt.html">Qt</a></span><span class="operator">.</span>locale(<span class="string">&quot;de_DE&quot;</span>);
  var d;
  d <span class="operator">=</span> Number<span class="operator">.</span>fromLocaleString(german<span class="operator">,</span> <span class="string">&quot;1234,56&quot;</span>)   <span class="comment">// d == 1234.56</span>
  d <span class="operator">=</span> Number<span class="operator">.</span>fromLocaleString(german<span class="operator">,</span> <span class="string">&quot;1.234,56&quot;</span>) <span class="comment">// d == 1234.56</span>
  d <span class="operator">=</span> Number<span class="operator">.</span>fromLocaleString(german<span class="operator">,</span> <span class="string">&quot;1234.56&quot;</span>)  <span class="comment">// throws exception</span>
  d <span class="operator">=</span> Number<span class="operator">.</span>fromLocaleString(german<span class="operator">,</span> <span class="string">&quot;1.234&quot;</span>)    <span class="comment">// d == 1234.0</span>

</pre>
</div></div><!-- @@@fromLocaleString -->
<br/>
<!-- $$$toLocaleCurrencyString -->
<div class="qmlitem"><div class="qmlproto">
<div class="table"><table class="qmlname">
<tr valign="top" class="odd" id="toLocaleCurrencyString-method">
<td class="tblQmlFuncNode"><p>
<a name="toLocaleCurrencyString-method"></a><span class="type"><a href="qml-string.html">string</a></span> <span class="name">toLocaleCurrencyString</span>(<i>locale</i>, <i>symbol</i>)</p></td></tr>
</table></div>
</div><div class="qmldoc"><p>使用指定区域的货币和约定将数字转换为货币。如果指定了符号，它将被用作货币符号。</p>
<p><b>请参考 </b><a href="qml-qtqml-locale.html#currencySymbol-method">Locale::currencySymbol()</a>.</p>
</div></div><!-- @@@toLocaleCurrencyString -->
<br/>
<!-- $$$toLocaleString -->
<div class="qmlitem"><div class="qmlproto">
<div class="table"><table class="qmlname">
<tr valign="top" class="odd" id="toLocaleString-method">
<td class="tblQmlFuncNode"><p>
<a name="toLocaleString-method"></a><span class="type"><a href="qml-string.html">string</a></span> <span class="name">toLocaleString</span>(<i>locale</i>, <i>format</i>, <i>precision</i>)</p></td></tr>
</table></div>
</div><div class="qmldoc"><p>以指定的格式和指定的精度将数字转换为适合于指定区域设置的字符串。</p>
<p>有效的格式是:</p>
<ul>
<li>'f' 十进制浮点数，例如248.65</li>
<li>'e' 使用e字符的科学记数法，如2.4865e+2</li>
<li>'E' 使用E字符的科学记数法，如2.4865E+2</li>
<li>'g' 用e或f的缩写</li>
<li>'G' 用E或f的缩写</li>
</ul>
<p>如果未指定<span lang="zh-cn">精度</span>，则<span lang="zh-cn">精度</span>将为2。</p>
<p>如果没有指定格式，将使用'f'。</p>
<p>如果未指定<span lang="zh-cn">区域</span>，则使用默认<span lang="zh-cn">区域</span>。</p>
<p>下面的示例显示了德语区域设置的格式化数字:</p>
<pre class="cpp">

  import <span class="type">QtQuick</span> <span class="number">2.0</span>

  Text {
      text: <span class="string">&quot;The value is: &quot;</span> <span class="operator">+</span>  Number(<span class="number">4742378.423</span>)<span class="operator">.</span>toLocaleString(<span class="type"><a href="qml-qtqml-qt.html">Qt</a></span><span class="operator">.</span>locale(<span class="string">&quot;de_DE&quot;</span>))
  }

</pre>
<p>你可以直接对常量应用toLocaleString()，只要常量中包含小数，例如。</p>
<pre class="cpp">

  <span class="number">123.0.toLocaleString</span>(<span class="type"><a href="qml-qtqml-qt.html">Qt</a></span><span class="operator">.</span>locale(<span class="string">&quot;de_DE&quot;</span>)) <span class="comment">// OK</span>
  <span class="number">123..toLocaleString</span>(<span class="type"><a href="qml-qtqml-qt.html">Qt</a></span><span class="operator">.</span>locale(<span class="string">&quot;de_DE&quot;</span>))  <span class="comment">// OK</span>
  <span class="number">123.toLocaleString</span>(<span class="type"><a href="qml-qtqml-qt.html">Qt</a></span><span class="operator">.</span>locale(<span class="string">&quot;de_DE&quot;</span>))   <span class="comment">// fails</span>

</pre>
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